Choker pass block for high lead logging



Fb. 4, 1958 H. E. MADSENJ 2, 37

5 CHOKER ms BLOCK FOR HIGH LEAD" poccmc Filed April 7, 1955 INVZN TOR HERLUF E. MAPSEN United States Patent CHOKER' P-ASS BLOCK: FOR mGH LEiADJ LOGGING. 1

uterine-E. Madsen, Stuartlslahd; British Columbia, Canada Application April 77,1955, Serial :Noa:49,9,9,46 v Claims. (Cl..104 11'5) My invention relates to improvementsin-choker=pass= blocks'for high lead logging:

carriage or trailing of logs carried by the choker line. In such instances, it hasbeen the custom to use skyline carriages and other expensive equipment, which make it unprofitable to log the smaller timber. tracts which. are still. available. in order to overcome this expense and equipment I provide'a single "block which may be suspended'from' a spa'r tree orotherwise adjacent theinterfering transverse ridge and pass the main and haul back line through said block at a suitable height andto allow the choker line attached to said main and haul back lines to be automatically unshipped from the main sheave of the block and carry its load freely suspended over the ridge. The invention makes it possible to yard over a great length of timber land and can be used to raise the main line to an appropriate point at more than one interval of the total length of the run yarded and to provide that the checker line may hang free from the main line either when loaded or otherwise.

Referring to the accompanying drawings:

Figure 1 is a general view showing the disposition of the invention in a high lead logging operation.

Figure 2 is a front elevation of the invention.

Figure 3 is a sectional view taken on the line 3-3 of Figure 2.

In the drawings like characters of reference indicate corresponding parts in each figure.

The numeral 1 indicates a frame which consists of a rear panel 2 having a hood 3 extending outwardly from its upper edge. The hood is formed with an inside under surface of two connected planes 4 at an obtuse angle to each other and on the top of the hood one or more eyes 5, or other members, are provided by which to suspended the block from a suitable support between the ends of the main line run. The lower part of the rear panel is provided with a horizontally disposed guard rail 6 which extends outwardly from the front face of the panel, as shown particularly in Figure 3. Mounted rotatably on the face of the panel to project therefrom is a susbtantially semi-spherical sheave 8 having a single rim 9 at its rear side. This sheave is mounted upon anti-friction bearings 11 from a horizontal centre pin 12. A lower portion of the main sheave 8 projects into the opening 14 formed by the guard rail 6.

Mounted for free rotation on the planes 4 of the hood 3 are two downwardly projecting guard rollers 15, the free ends of which are rounded longitudinally as at 16. These rollers 15 have their peripheral edges spaced from the rear panel 2 to allow free passage of a main line 18 therebetween and to serve in keeping said main line parallel with the panel and confine said line upon the semispherical sheave 8 and in normal contact with its single rim 9. The rounded lower ends 16 of the rollers 15 are 2; spaced' from the peripheral: surfacesrof the sheave 8 sufficient to allow a. choken line lSl to pass transverselyrbe tween them as 'indicatedw ini dotted lineiin: Figure ii: The

main line 18 will preferablytbe connected assindicatedw i111 Figure 2 by' a 1 linkage21rtoiaihaulback @line" 22 and the checker line 19 is connectedwasiatt 23 to said Z linkage; so that said" choker" line can: swing .freely. in "any direction relative to the-main and:haul back linesrl8 andz2li.

When in use, a load maytbe 'connected to therfr'eeendi. of the choker line sayvadjacent ther-end of the run close to the haul back 'block 25 and may bebrouglit to a pointzotu delivery adjacent the main lineabloclc sparrtreef 26, .the choker pass block 27 isset at asuitalblyrhigh point above the ridge 29 so that the load; maya'freelyxpass over the ridge. When the mainline is drawn'int'in the usual. way; to' move the load towards the point ofidelivery; theloade. attached to the free end of the choker :line} 19 =will'.:be lifted-or trailed inpart contact'with. the ground. When the linkage 21 between the mainiline and' the haulhack: line reaches the-choker pass block' 27 the leadingzend'of: the haul back line: and the adjacent end-of the choker: line will pass between the. nearest; roller 15 and 'therear; panel 2 and onto the periphery'tof the semi-spherical: sheave 8. At this point themain and haul'ing lines will be inaligned horizontal position-andfiwill be-s'o' held by the. substantially verticalrollers il 5-, but the -weight of the-load. on the choker line willcause said-line-to slip-outwardly; along the peripheral surfaceof thesemi-spherical sheave and around its end, sliding outwardly through a passage X between the first encountered roller and inward across the end of said sheave through another passage X and between said sheave and the second roller 15 to hang downwardly below the linkage 21 or connection between the ends of the several lines and pass outwardly when so suspended between the last mentioned roller and the rear panel 2 of the choker pass block. The main and haul back lines can be run in either direction and the choker line, whether loaded or otherwise, will move automatically and at any normal speed around the end of the sheave 8 to maintain its normal position relative to said lines.

What I claim as my invention is:

l. A choker line pass block for high lead logging through which a main line and a haul back line and part of a choker line are adapted to pass, said block comprising a vertical panel having a hood extending horizontally therefrom, said block being provided with means for suspension from a support, a sheave rotatably mounted on a center pin extending horizontally from the vertical panel below the hood, said sheave being spaced below the hood to define a passage parallel to the face of the panel for the endwise movement of said main and haul back lines and part of said choker line attached to said main and haul back lines, a member spaced from the face of the panel and projecting downwardly from the hood and beyond the upper periphery of the horizontal sheave, said downwardly projecting member and the outer end of the horizontal sheave defining a gap, the end of said horizontal sheave being shaped to facilitate the slipping off of a part of the choker line to pass freely through said gap as said main line and haul back lines are moved lengthwise of the passage parallel to the said face of the panel.

2. A choker line pass block for high lead logging as claimed in claim I, wherein a pair of downwardly projecting members project from the hood on opposite sides of a vertical plane taken through the axis of the sheave and spaced from said face of the panel.

3. A choker line pass block for high lead logging through which a main line and a haul back line and part of a checker line are adapted to pass. said block comprising a vertical panel and having means for suspension from a support, a horizontal sheave rotatably mounted adjacent the center of the panel, a pin extending normally to a face of said panel, said sheave being mounted upon said pin and having a rim at one end adjacent the face of the panel, a member depending from above the sheave and carried in spaced relation from the panel, said panel, sheave and depending member defining a passage through which said main and haul back lines and a connected part of said choker line may pass along the face of the panel and said depending member being spaced to one side of the sheave to define a gap through which the choker line connected to the main line may pass.

4. YA choker line pass block as claimed in claim 3,-

wherein two depending members are provided, one on each side of the sheave and spaced therefrom, whereby to allow the choker line connected to the mainline to pass between one of said members and the sheave around an end of said sheave and between the second of-said members and the sheave as the main line'is moved endwise across the panel. v I

5. A choker line pass block for high lead logging as claimed in claim 3, wherein the horizontally mounted sheave has one side lying substantially in the plane of the adjacent face of the panel and the opposite'side is convexed to facilitate the passage of the choker transversely across said sheave. I

6. A choker line pass block for high lead logging as claimed in claim 1, wherein the downwardly projecting member spaced from the vertical panel is a roller freely rotatable upon a pin carried by the hood.

7. A choker line pass block for high lead logging as claimed in claim 1, wherein a pair of downwardly projecting members project from the hood on opposite sides of a vertical plane taken through the axis of the sheave and spaced from said face of the panel, said downwardly projecting members being rollers freely rotatable upon pins carried by the hood.

8. A choker line pass block for high lead logging as claimed in claim 1, wherein the downwardly projecting member is a roller freely rotatable upon a pin carried by the hood and said roller is rounded at its lower end.

9. A choke line pass block for high lead logging as claimed in claim 1, wherein a pair of downwardly projecting members project from the hood on opposite sides of a vertical plane taken through the axis of the sheave and spaced from said face of the panel, said downwardly projecting members being rollers freely rotatable upon pins carried by the hood and said rollers being rounded at their lower ends.

10. A choker line pass block for high lead logging as claimed'in claim 1, wherein a guard rail projects from the vertical panel beyond the front side of the sheave to guide the choker line across the face of the sheave.

References Cited in the file of this patent I UNITED STATES PATENTS Germany a Apr. 23, 1953 

